Fault diagnosis methods for the vibration system of road rollers

To diagnose faults in a timely manner, pressure measurement ports have been set up at key parts of the hydraulic system of the roller. Users can conveniently and quickly locate faults by using the pressure gauge equipped on the roller, reducing the time for troubleshooting and maintenance. This article takes the YZ14GD vibratory roller produced by our factory as an example to introduce a set of fault diagnosis systems.

If the rated speed of the diesel engine is normal, the roller can be driven 10 meters front and back respectively to ensure that the oil seal of the vibrating bearing box is fully lubricated. Then stop the vibrating wheel on the old rubber tire, shift it into neutral, start the diesel engine and run it at the maximum speed. Hold the spring-type frequency meter with your palm and place it on the front frame. Start the vibration in a very short time to see if the measured vibration frequency is 31Hz (at this time, the corresponding eccentric shaft speed is 1860r/min).

If the vibration frequency is measured to be low, the oil leakage rate of the vibration motor should be checked. Run the roller to a working oil temperature of 500 ° C. Stop the vibrating wheel at the opening of the old rubber hose. The measuring hose is connected to the oil drain port of the motor, and the other end is placed in the metering bucket. Start the diesel engine at maximum speed and activate the vibration. The oil leakage should not exceed 2.5L/min. If the value exceeds this limit, the motor should be inspected and repaired.

If the oil leakage rate of the motor is within the allowable range, the pressure of the vibration circuit should be checked. Run the roller to the working oil temperature (hydraulic oil temperature 500 ° C), stop the vibrating wheel on the old tire, and pad the drive wheel with triangular blocks. Connect a 60MPa pressure gauge to the test port of the vibration system with a test hose. Start the diesel engine at maximum speed, activate the vibration, and observe the pressure gauge. The starting pressure (the reading on the pressure gauge when the motor is just started) should be 19 to 21MPa, and the working pressure (the reading when the vibration motor is running smoothly) should be 8 to 11MPa. If the starting pressure is low, the vibrating pump should be inspected. If the working pressure is significantly higher than 11MPa, the vibrating bearing should be inspected.

When the working pressure is significantly higher than 11MPa, the vibration motor should be removed to check the axial clearance of the vibration bearing. When pushing the vibration shaft along the axial direction for inspection, there should be an axial movement of 1 to 2mm. Check the radial clearance of the vibrating bearing again. Apply radial force to the eccentric shaft with a crowbar. If a distinct movement can be felt, the bearing must be replaced. Finally, check the free movement condition of the vibration shaft. Install a hexagonal head bolt on the screw hole at the end of the vibration shaft. Use a socket wrench to turn the bolt clockwise by 1900C, and then release the wrench. If there is obvious resistance felt during several free oscillations, the bearing should be replaced.

If the starting pressure in the vibration circuit is low, the high-pressure hose on the vibration pump should be removed, the oil pipe interface should be sealed with a plug head, a 60MPa pressure gauge should be connected to the high-pressure port of the vibration pump, and the diesel engine throttle lever should be placed in the stop and stop position. Rotate the diesel engine with a starter motor. If the pressure does not reach 10MPa, replace the pump. If the pressure reaches 10MPa, check the starter control valve.

When inspecting the start control valve, the screws of the wire joints should be loosened. If the vibration switch is turned on and there is no electricity at the contact point of the socket, then look for faults in the circuit system and whether the battery voltage is sufficient. Take out the seat cover, loosen the nut on the electromagnetic coil, and remove the wire and socket together. Connect 12V DC power to the socket and use a screwdriver to test if the magnetic field has been established. If there is no magnetic field, the coil should be replaced. If there is a magnetic field, replace the vibration valve.